333 results about "Heat transfer model" patented technology

An approach to noninvasively, remotely and accurately detect core body temperature in a warm-blooded subject, human or animal, via thermal imaging. Preferred features such as the use of in-frame temperature references, specific anatomical target regions and a physiological heat transfer model help the present invention to overcome pitfalls inherent with existing thermal imaging techniques applied to physiological screening applications. This invention provides the ability to noninvasively, remotely and rapidly screen for diseases or conditions that are characterized by changes in core body temperature. One human application of this invention is the remote screening for severe acute respiratory syndrome (SARS), since fever is a common, early symptom. Other diseases and conditions that affect the core body temperature of humans or animals may also be noninvasively and remotely detected with this invention.

The invention discloses a quasi-continuous laser metal 3D printing method capable of realizing regulation of nickel base alloy crystallographic texture. Laser output is set as a quasi-continuous lasermode, and then a laser metal 3D printing technical window is preliminarily optimized. The temperature field of a molten bath under the preliminarily optimized parameter is calculated by using a finite element heat transfer model; the temperature gradient G and the cooling rate xi of the moving boundary of the molten bath during closing of laser in a single pulse period are extracted, and the growth length L of a single pulse internal columnar dendrite is worked out according to a structure growth theoretical model; the laser parameter is optimized according to the matching rule that the ratioof the scanning speed V to pulse frequency f is 0.5-0.8L, and finally 3D printing forming is conducted according to the optimized parameter, so that a formed part with the consistent crystallographicorientation height is obtained. By regulating the heat source output mode, an effective remelting mechanism for mixed crystal or isometric crystal is introduced in the scanning direction, all columnar dendrite growth is obtained, and the consistency of grain orientation is remarkably improved.

The present invention discloses an online comprehensive control method for a hot-galvanized continuous annealing furnace. The method collects the operating information, including band steel speed, processing technique, steel coil codes and band steel specifications, of band steel through an online detection module. According to the collected operating information of band steel, the method calls main parameters through an expert database, so as to complete thermal load setting and speed setting by the co-operation of a speed model, a heat transfer model and a band temperature feedback model. Therefore, according to the set parameters, the method automatically controls a primary control system, so as to achieve the online production control of an annealing furnace. Based on heat transfer mechanism analysis, the method achieves the online production control of an annealing furnace by building a one-dimensional math model and the expert database with two cross-control methods: coarse tuning and fining tuning. In addition, the method also provides an additional series of complete control strategies such as a transition control method, so as to form a relative perfect control method. The models can be built conveniently and operate fast. Therefore, the method is suitable for the online production computation and control of an annealing furnace.

The invention discloses an intelligent monitoring method for a blast furnace cooling wall, which comprises the following steps that: a cooling wall heat transfer model is established, a heat transfer core model is extracted through a non-linear regression mode, the core model and an artificial neural network are combined to produce a monitoring model for a highest temperature value of a hot surface of the cooling wall and form monitoring software, and the running state and local high-temperature positions of the cooling wall as well as the safety of the cooling wall are evaluated by combining the heat transfer model with temperature values of test points of an in-situ sensor. The method has the advantages of simple data acquisition for theoretical analysis, quick and accurate result generation, and less damage to shells of blast furnaces.

Generating a heat transfer model for building energy may comprise developing a PDE model that describes heat transfer through building envelope of a building, and developing an ODE model that describes the heat transfer and thermal balance in a space inside the building. Stepwise parameter estimation integrates the PDE model and the ODE model in generating the heat transfer model.

The invention relates to a ground source heat pump rock-soil heat response dynamic testing system, which consists of a heating water tank, a circulating pump, a bypass-valve, a heating well, a U-shape pipe, a temperature monitoring well, a data acquisition analyzer, temperature sensors, flow sensors and a heater, and is characterized in that the temperature monitoring well is arranged in the position 0.3-1.2 m away from the heating well, a temperature sensor group identical to temperature sensors group on the heating well is arranged in the temperature monitoring well, and all the temperature sensors and flow sensors are connected with the data acquisition analyzer through signal lines. In testing, a rock-soil original temperature value data test, a basic heating process data test, a strengthened heating process data test and after heating stop data test are respectively carried out on the heating well and the temperature monitoring well. By the comparison of a calculation value and a measured value of a heat transfer model and the revision of rock-soil thermal conductivity, the actual rock-soil thermal productivity is ultimately approximated. The rock-soil temperatures in the heating well and the temperature monitoring well are monitored synchronously to shorten the test time; and the heat transfer conditions of rock-soil at different depths and the mutual influence of wells are accurately mastered to provide data for designing.

The invention discloses a method for predicting the junction temperature of an IGBT (Insulated Gate Bipolar Translator) module. The method comprises the following steps: 1) according to parameters of a modularized multi-level circuit and the running condition thereof before shortcircuit, calculating an expression of current flowing through the IGBT during direct-current bipolar shortcircuit; 2) according to an IGBT data sheet, fitting relational expressions between the conduction loss and the current flowing through the IGBT and between the switching energy and the current flowing through the IGBT; 3) according to the equivalent switching frequency and the equivalent duty ratio of the IGBT, judging the switching state of the IGBT; 4) according to the switching state of the IGBT, the expression of the current flowing through the IGBT during the direct-current bipolar shortcircuit, and the relational expressions between the conduction loss and the current flowing through the IGBT and between the switching energy and the current flowing through the IGBT, calculating a loss value P of the IGBT; 5) according to the loss value P of the IGBT and a fourth-order Foter heat transfer model of the IGBT module, calculating a distribution value of the junction temperature of the IGBT along with time. The method is applied to the modularized multi-level circuit, and is used for predicting a junction temperature change curve during the direct-current bipolar shortcircuit under different running conditions through calculation; by the method, a reference is provided for main circuit design, protection design and cooling circuit design, and the stability of a system is improved.

The invention discloses a method for carrying out in-situ on thermophysical parameters of cylindrical winding type lithium ion batteries. The method comprises the following specific steps of: firstly,building an experiment device, heating a battery by using an external heat source according to certain power, and measuring different instantaneous temperature changes of a plurality of points on thebattery; secondly, establishing a heat transfer model which comprises heat conductivity coefficient parameters and specific heat capacity parameters of the battery in different directions in simulation software, and calculating a numerical solution of temperature change at each thermocouple measuring points; and finally, fitting measured temperature values and simulated values, and obtaining specific data of thermophysical parameters of the battery. The method has the beneficial effect of considering wet type structures, namely, electrolyte, in real batteries and contact thermal resistance between different structure layers, so as to in-situ and correctly obtain important thermophysical parameters of batteries, such as heat conductivity coefficients and specific heat capacities.

The invention discloses a non-contact tube pass fluid temperature measuring method based on temperature measurement of a pipeline outer wall. The measuring method includes the steps that pipeline and external environment parameters are collected, and the flow speed of internal fluid is determined, so that the pipeline heat transfer process is divided into natural convective heat transfer between the pipeline outer wall and air, pipe wall heat conduction and forced convective heat transfer between the pipeline inner wall and water at three levels; a heat transfer expression is obtained after a radial-direction heat transfer model of a pipeline is set up, the expression is iteratively and repeatedly calculated to obtain the needed tube pass fluid temperature value. The non-contact measurement of the tube pass fluid temperature is achieved, the applicability is good, on the premise of guaranteeing real-time performance, measurement accuracy and detection efficiency are improved, and the non-contact tube pass fluid temperature measuring method can be suitable for fast measuring tube pass fluid temperature under various conditions.

The invention provides a method for analyzing and monitoring the erosion of a furnace lining of a blast furnace, comprising the following steps of: (1) radially and uniformly arranging thermocouples along a furnace cylinder; (2) establishing database connection and introducing fire-resistant materials and cooling system parameters; (3) establishing a boundary condition and establishing a heat transfer model according to the introduced data in the step (2); (4) analyzing numeric values of the heat transfer model by using a computer according to measuring values of the thermocouples to finally acquire an isotherm position; and (5) writing a model calculation result into the database, displaying the change and the shape of the position of eroded boundary after the computer reads the database in real time, and storing the calculation result to form history data and history curves. The method avoids the quickening of the erosion speed and the ring crack of carbon bricks, simultaneously prevents the furnace cylinder from thickening to influence the smooth operation of the blast furnace, and further prevents piling of the centre of the furnace cylinder and the erosion phenomena of the boundary of the furnace cylinder and the furnace bottom; and simultaneously guides the operation of the blast furnace, in particular to adjustment of cooling water quantity, and ensures that heat flow intensity of the furnace cylinder and the furnace bottom is in the proper range.

The invention relates to a square lithium ion battery internal thermophysical parameter identification method and belongs to the field of lithium ion batteries. According to methods for directly obtaining the analytical solutions of heat transfer model equations in existing battery thermophysical parameter identification methods, the overall parameters of batteries are identified, and the internalthermophysical properties of the batteries cannot be identified, while, with the square lithium ion battery internal thermophysical parameter identification method of the invention adopted, the problems in the existing methods can be solved. According to the square lithium ion battery internal thermophysical parameter identification method of the invention, the internal specific heat at constantpressure of a battery is obtained according to battery shell and internal mass, the specific heat at constant pressure of battery shells, heating power and the relation of the temperature of the battery varying with heating time; and the internal longitudinal thermal conductivity coefficient of the battery is obtained according to a heat transfer process, specific heat capacity and boundary conditions; two thermocouples on each battery shell are adopted to obtain two temperatures, and the temperatures of two temperature points at the inner sides of an equal thickness of the lithium ion batteryshells are obtained according to the longitudinal thermal conductivity coefficient and a heat transfer model; and on the basis of the two temperature points and the boundary conditions, the transverse thermal conductivity coefficient of the internal material of the battery is obtained according to the heat transfer model. The method is used to identify the internal thermophysical parameters of the battery.

The invention discloses a laser metal 3D printing method capable of achieving customization of local solidification structures of a nickel base functional part. The laser metal 3D printing method comprises the steps of drawing a correspondence relationship diagram of nickel base alloy solidification structures and solidification parameters; acquiring the solidification parameter range corresponding to a local target structure of the part according to the diagram; calculating a molten pool temperature field through a three-dimensional finite element heat transfer model, representing the solidification parameter range, and acquiring technological parameters matched with the target structure; matching all the solidification structures of the part with the technological parameters according tothe process; carrying out single-layer slicing treatment on the part, and acquiring technological parameters, changing along with positions, of a single layer till slicing and setting of technological parameters of all the layers of the part are achieved; and inputting the customized technological parameters into a 3D printing system, carrying out 3D printing, and acquiring the nickel base functional part with the customized solidification structure. According to the laser metal 3D printing method, the customized technological parameters are adopted according to the requirements of the localstructures of the part, and customization of the local solidification structures of the part can be effectively achieved.

The invention discloses a charging method of a lithium ion battery. The charging method comprises the following steps: establishing an equivalent circuit model of the lithium ion battery through a neural network; coupling a heat transfer model on the basis of the equivalent circuit model to establish an initial electric-thermal coupling model; designing a plurality of groups of constant-current charging schemes; testing a battery to be detected according to the constant-current charging schemes so as to obtain a plurality of groups of testing data; designing a plurality of groups of multi-phase charging schemes and inputting the plurality of groups of multi-phase charging schemes meeting constraint conditions of a multi-target optimization model into a target electric-thermal coupling model in sequence, so as to obtain result data; carrying out iterative optimization on the result data based on the multi-target optimization model and selecting one group of Pareto optimal solution from the plurality of groups of multi-phase charging schemes as a charging scheme for selecting; and selecting a target charging scheme from the charging scheme for selecting through a decision-making scheme. According to the charging method disclosed by the invention, the optimal charging scheme can be provided for battery charging by utilizing limited experiment times.

The invention discloses an indirect measuring method for cable core temperature. The method comprises the following steps: 1, establishing a theoretical heat transfer model of a cable; 2, calculating model parameters in the theoretical model; 3, measuring running data of partial parameters of the cable; 4, calculating the cable core temperature of the cable through the model parameters and the measured running data to finish indirect measurement. The indirect measuring method has the advantages of easiness, rapidness and accuracy.

The invention provides a method for measuring thermophysical property of a columnar thermal insulation material, which is used for determining radial heat conductivity, axial heat conductivity and volume heat capacity of the columnar orthotropic thermal insulation material by measuring temperature variation of one point of a tested sample. The method comprises the following steps: establishing a two-dimension cylindrical coordinate heat transfer model under effect of thermal interference of specific form in cylindrical coordinates; obtaining analytical solution of temperature variation of the orthotropic thermal insulation material in the time domain by adopting Laplace transformation, Hankel transformation and Laplace inverse transformation; analyzing correlation among sensitivity coefficients of the radial heat conductivity, the axial heat conductivity and the volume heat capacity and the influences of temperature variation caused by the parameters through calculation on the sensitivity; establishing a corresponding measurement system, and acquiring the transient response data of the temperature in real time; and meanwhile, determining the radial heat conductivity, the axial heat conductivity and the volume heat capacity of the tested orthotropic thermal insulation material by adopting an L-M parameter estimation method. The method provided by the invention is convenient to implement and adopts simple steps, and meanwhile can be used for measuring the radial heat conductivity, the axial heat conductivity and the volume heat capacity of the columnar thermal insulation material.

The invention discloses a data heat transfer model-based testing device and a testing method thereof. The device consists of a water tank, a thermostatic heating pipe, a water pump, a valve, a thermometer, a temperature sensor, a pressure gauge, a flow meter, an electric power sensor, a U-shaped embedded pipe, a data processor and a control switch. The thermal physical parameters of tested rock soil can be obtained according to the water temperature change values of an inlet and an outlet of the U-shaped embedded pipe, flow and pressure values of water and original soil temperature value acquired by the temperature sensor through a one-dimensional unsteady state value model by adopting a comprehensive calculation method.

A method for predicting fluid temperature distribution of a vertical single U-shaped buried pipe of a ground source heat pump under variable operating conditions belongs to that field of ground sourceheat pump, and is used for calculating fluid temperature distribution in U-shaped pipe under variable heat flux or variable inlet fluid temperature operating conditions. Firstly, a single U-shaped buried pipe is simplified to an equivalent pipe based on the equivalent pipe diameter method, and a one-dimensional radial heat transfer numerical model including fluid, equivalent pipe, backfill and soil is established, and the heat transfer equation is discretely solved to calculate the average temperature of the fluid in the single U-shaped buried pipe. The results show that the average temperature of the fluid in the U-shaped buried pipe is higher than that in the single U-shaped pipe. Then, based on the quasi-three-dimensional heat transfer model in the borehole, the relationship between the inlet fluid temperature and the average wall temperature of the borehole with respect to the average fluid temperature and heat flux is established, and the fluid temperature distribution in the U-tube under the conditions of variable heat flux or variable inlet fluid temperature is calculated. This method has the advantages of less computation, high precision and strong generality.

The invention discloses a control method of a vertical annealing furnace based on band steel switching specifications, belonging to the technical field of automatic control. The control method comprises the following steps: firstly judging whether the types, thickness and target temperature intervals of two kinds of band steel in front of and behind a weld joint are consistent to determine the types of replacing bands by periodically acquiring the specifications of the two kinds of band steel subjected to band replacement and the weld joint location information; then determining the band replacing target temperature according to the types of the replacing bands and computing the band steel velocity set values and radiant tube temperature set values at different stages during band replacing according to combined action of a velocity model and a heat transfer model; finally judging different stages during band replacing according to the weld joint location and giving the band steel velocity set values and radiant tube temperature set values at corresponding stages, thus achieving the aim of stable control. The perfect control method can be formed and is applicable to online band replacing control of the vertical annealing furnace.